Clamp for joining stout planks and timbers, more particularly for use in concrete shuttering



Jan. 20, 1959 G. J. AXELL 2,869,

CLAMP FOR JOINING STOUT PLANKS AND TIMBERS, MORE PARTICULARLY FOR USE IN CONCRETE SHUTTERING Filed Dec. 12, 1955 2 Sheets-Sheet 1 Jan. 20, 1959 G. .AXELL 2,86

AND I BERS, MORE CLAMP FOR JOINING ST U PLA PARTICULARLY FOR USE IN C RETE UTTERING Filed Dec. 12; 1955 V 2 Sheets-$118M 2 United States Patent CLAMP FOR JOINING STOUT PLANKS AND TIMBERS, MORE PARTICULARLY FOR USE IN CONCRETE SHUTTERING Giista Julius Axell, Linkoping, Sweden Application December 12, 1955, Serial No. 552,537 Claims priority, application Sweden December 15, 1954 6 Claims. (Cl. 20-92) of a base plate or fitting secured to one of the said timber beams, and a stirrup hinged to said fitting, the said stirrup lncludes a shackle bolt portion rotatably held in a sleeve extending along the upper edge of the fitting, two side members fixed to the ends of the said bolt, and a cross member that joins the side members together across the far side of the second member beam opposite the said base plate or fitting. The side members are each provided with a sliding surface, the one being inclined inwards and the other outwards when viewed from the shackle bolt. The base plate or fitting carries an upstanding pin upon which is fulcrumed a transverse doublearmed lever. The length of the arms is such that they can be swung into engagement with and wedged under the sliding surfaces of the side members. Owing to the wedge effect of the arms the stirrup is forced tightly against the timbers and presses them firmly together.

The invention will now be more particularly described with the aid of and by reference to the accompanying drawings.

Fig. 1 is a front view of one form of construction of the clamp,

Figure 2 is a left hand side view of the left side portion 1 only of the same clamp,

Fig. 3 is a view from the back,

Fig. 4 is a right-hand side view of the right side portion only of the clamp, and

Fig. 5 is a side view of an alternative form of construction of a clamp according to the invention.

In the form of construction shown in Figs l to 4 two stout timber planks have been placed with their flat sides face to face and firmly bound together with two clamps constructed according to the present invention. These clamps press the stout plank 1 against the plank 2 and the friction between the two planks prevents them from slipping. Each clamp comprises a base plate or strap member 3 secured to one of the planks 2, and a stirrup member including a shackle bolt portion cut for instance from a length of round bar, is rotatably held by or hinged to a sleeve 5 fitted to the upper edge of the base plate or strap member 3. Attached to one end of the shackle bolt portion 10 is a side bar 6 extending nearly straight downwards from the end of the sleeve but with a slight outward slant relative to the edge of the plank 2. At its lower extremity this side bar 6 is bent to extend across the adjacent sides of the two planks 1, 2, to form a transverse portion 7 which is somewhat longer than the combined thickness of the two planks 1 and 2 taken together and which on the far side is again bent at right angles across the outer face of the second manner that the plates are held parallel.

plank 1 to form a cross member 8. At the other edge of the plank 1 the cross member is again bent round the edge of the plank to form a portion 9 whichis substantially parallel to the above-mentioned transverse portion 7. However, the portion 9 is rather shorter than the portion 7 and at its end it is bent at an'angle to form a final side portion 4 which runs substantially upwards but with a slight outward slant relative to the edge of the plank 2. Level with the sleeve 5 this portion 4 is joined to the shackle bolt 10 by means of a short stub end portion 11 bent at approximately a right angle to the base plate 3. The center of the base plate 3 carries an upright pin 12 upon which is fulcrumed the center of a double-armed lever 13. This lever 13 is of suflicient length to allow its ends to'be swung or turned into engagement with, and wedged under, the side portions 4 and 6 of the stirrup, which extend substantially along the edges of the plank 2. As the ends of the arms are wedged under the said slanting side portions 4 and 6, the cross member portion 8 of the stirrup which runs across the far side of the second plank 1 is forced inwards and presses thetwo planks 1 and 2 together. To reinforce the stirrup it is expedient to brace the portions 4 and 6 which run substantially along the edges of the plank -2 and the portions 7 and 9 which extend across the narrow'sides of the two planks 7 and 9 by means of a stay or strut 14 that extends between them. It is also advisable to provide the cross member 8 of the stirrup which runs across the back of the plank 1 with a serrated or pronged plate 15. The double-armed lever 13 is equipped with means whereby it may be easily turned or swung into the locking position, for instance it may be provided with a hexagonal collar or projection 16 secured to the lever 13 around the pin, or alternatively two upstanding lugs 17 may be arranged on the lever 13 on either side of its fulcrum 12. It may also facilitate the operation of the lever 13 if its ends are wedge-shaped as at 13 at an angle that corresponds with the slant of the portions 4 and 6 so that the lever arms may be the more readily forced underneath the said portions 4 and 6 of the stirrup.

In an alternative form of construction shown in Fig. 5 the two stout planks are again placed together with their fiat sides face to face. The outside surface of the one plank 2 is similarly provided wtih a base plate 3 which extending along its upper edge carries a sleeve 5. The sleeve 5 is adapted to enclose a round shackle bolt 10 rotatably housed therein. The ends of said bolts are at tached to two substantially triangular plates 18, the point of attachment being near one of the corners of said plates. Two other corresponding corners of the two plates are joined by means of a cross member 19 in such The distance between the shackle bolt 10 and the cross member 19 exceeds the combined thickness of the two planks 1 and 2. Along their edges opposite the corners which are joined together by the cross member 19 the two plates 18 are each provided with a punched out slot 20 and 21 respectively. The strips of metal punched out of the slots are preferably not detached from the upper edge of the slots but allowed to stand out from the plate at right angles.

At its center the base plate 3 carries an upright pivot pin 12 upon which a double-armed lever 13" is fulcrumed, said lever being constructed substantially as has been described with reference to the previous exemplary form of construction. The lever 13" is so located that its two arms can be swung into engagement with and into the two above-mentioned slots 20, 21. The two slots 20, 21 on the side plates are longitudinally inclined in opposite directions, and the distance between the center oftheslots 20, 21 and "the inner edge of the cross piece 19 is nearly equal to the "combined thickness of the two planks 1, 2. When the ends of the doublearmed lever 13" are formed into the slots 20, 21 their effect is to draw thecross'piece 19towardsthe-rear'plank 1 and thereby to press the two planks tightly together.

It has been found to "be an advantage if the cross piece '19 is 'provided with a sharp edge facing the rear plank 1,'the edgeof the cross piece forming a wedge of about 90, or alternatively to provide the cross piece-With serrations or the like which assistin preventing the planks from'slipp'ing 'by biting into and gripping the outside face of plank].

Although only two exemplary forms of construction have been described it will be readily understood that the principle oftheinventioncan'be applied to numerous alternative forms of construction and that the invention is not limited in scope by the examples that have bee hereinabove described and illustrated.

What I claim is: 1. In "a 'clamp for securing together face to face two timbers or the like having plane faces in contact with each other comprising 'a strap member to be secured to a face opposite to thecontact face of one of said member each having a surface adapted to be engaged -by-one of the respective ends of the lever and the two surfaces being inclined in opposite directions in relation to the contact faces whereby rotation of the lever in one direction causes the clamp to press the timbers together.

2. A clamp according to claim 1, wherein the stirrup has its sides braced for strength.

'3. A clamp according to claim 1 wherein the double ended lever isprovided with means to facilitate turning it into engagement with the sides of the stirrup.

4. A clamp according to claim 1, wherein the doubleended lever is provided with an hexagonal central projection.

5. A clamp according to claim 1, wherein the double ended lever is provided with two lugs, one-on each side of the fulcrum of the lever, for the purpose of facilitating forcing said lever into engagement.

6. A clamp according to claim 1, wherein the ends of the double-ended lever are .provided with wedge portions inclined to correspond with the inclined surface on each sideof the stirrup so as to facilitate engagement.

References Cited in the file of this patent UNITED STATES PATENTS 1,097,285 Bag'by May 19, 1914 1,153,552 'Hunkin Sept. 14, 1915 1,269,964 Schenk June 18, 1918 1,495,043 Priebe May 20, 1924 1,778,350 Bosco Oct. 14, 1930 

